资料介绍
The recent interest in intelligent power supplies has
driven the development of a new class of microcontrol-
ler friendly PWM generators. These PWM generators
are the mixed signal control blocks for Switch mode
power supplies. One such device is the MCP1630. The
MCP1630 contains the 3 main elements for designing
a switching power supply as a peripheral to a microcon-
troller: a set/reset flip-flop, a high-speed voltage
comparator and an op amp to implement the error
amplifier (see Figure 1).
The microcontroller controls the MCP1630 through its
clock input. The frequency of the clock determines the
pulse frequency of the PWM output, and the duty cycle
of the clock limits the maximum PWM duty cycle of the
output. Control of the duty cycle between 0 and the
maximum set by the clock input is determined by the
current feedback to the comparator and the output of
the error amplifier (see Figure 2). TB085
A Simple Circuit for Driving Microcontroller
Friendly PWM Generators
Because the MCP1630 does not contain an on-chip
Author: Keith Curtis
Microchip Technology Inc. oscillator, its application in non-intelligent or dumb
power supply designs, is limited. However, marrying
the MCP1630 with a small pin-count microcontroller
INTRODUCTION solves the oscillator pro
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